A known object detection apparatus transmits and receives pulse probe wave such as ultrasonic wave and electromagnetic wave to detect an object existing in a probe wave illumination range. Because of directionality of the probe wave, when the probe wave is transmitted in a horizontal direction, the received reflected wave may contain noise resulting from road surface reflection.
A technology for addressing this problem is disclosed in, for example, Patent Literature 1. The technology is provided with an onboard camera for imaging a road surface and determines a threshold for noise removal in accordance with a road surface condition determined by the captured image and removes the noise.